2.2Unit 3: Forces, motion and pressure

Speed — Cambridge Checkpoint Physics 0893 Revision Notes & Topical Questions

5 min read 9 parts Lesson 2 of 7 1 quiz

📚 Cambridge Checkpoint Physics 0893 Hub / Topical Revision

0%read

Lesson summary

2.2 Speed — CHECKPOINT PHYSICS 0893 notes: Define speed, state its units and calculate speed, distance and time.Different units — knots for ships, Mach for aeroplanes, and km/h or miles per hour for road speed limitsStandard unit — scientists use metres per second (m/s) in all co…

Average speed
Formula triangle
Same units
Independent variable
Controlled variables
Standard unit — scientists use metres per second (m/s) in all countries

Part 1 of 8Units of speed

Different units

Different units knots for ships, Mach for aeroplanes, and km/h or miles per hour for road speed limits

Standard unit

Standard unit scientists use metres per second (m/s) in all countries

Per

Per in each, so a horse at 15 m/s travels 15 metres in each second

Part 2 of 8Calculating speed

Equation

Equation speed = distance ÷ time

Bus

Bus a bus that travels 100 m in 20 s has a speed of 5 m/s

Constant

Constant not changing

Average speed

Average speed total distance ÷ total time, used because the speed in a journey is not always constant

Part 3 of 8Rearranging the equation

Distance

Distance distance = speed × time

Time

Time time = distance ÷ speed

Formula triangle

Formula triangle cover the quantity to find and use the remaining two as shown

Part 4 of 8Equations summary

To find	Equation	Standard unit
Speed	distance ÷ time	m/s
Distance	speed × time	m
Time	distance ÷ speed	s

Part 5 of 8Using other units

Same units

Same units if distance is in km and time in hours, the speed comes out in km/h

Aeroplane

2500 km in 5 hours is 500 km/h

Default

Default unless told otherwise, work in metres, seconds and metres per second

Working

Working show the steps and include the correct unit with the answer

Part 6 of 8Typical speeds

Method of travel	Typical speed (m/s)
Walking	2
Horse riding	10
Bus	12
Small motorcycle	20
Car	30
Train	35
Aeroplane	200

Part 7 of 8Investigating the speed of a ball on a ramp

Fix the bottom of the ramp to the desk and put coloured tape on the desk at set distances from the end of the ramp.

Fix tape near the top of the ramp to mark the release position and measure its height.

Release the object and time it between the two pieces of tape on the desk.

Repeat twice more and calculate the average time.

Repeat for a range of heights and calculate the speed for each.

Plot a line graph with height on the horizontal axis and speed on the vertical axis.

Part 8 of 8Variables in the ramp investigation

Independent variable

Independent variable the release height

Dependent variable

Dependent variable the speed between the two pieces of tape

Controlled variables

Controlled variables the object, the distance between the pieces of tape and the ramp surface

Repeating

Repeating it gives an average and shows anomalous results

Trend

Trend the greater the release height, the greater the speed

Key terms

Term	Meaning
Speed	Distance travelled per unit time.
Average speed	Total distance divided by total time.
Metres per second	Standard unit of speed, m/s.
Constant	Not changing.
Formula triangle	Memory aid for rearranging an equation.

Avoid these mistakes

Using km/h with seconds in the same calculation — keep units consistent.

Forgetting the unit in the answer — speed needs m/s, km/h or another unit.

Using the formula triangle the wrong way up — distance is on top.

Calling the speed constant when it varies — use average speed for a whole journey.

Last updated: 12 October 2026